'Twelve' in the Bible

Therefore Jesus said to the Twelve, “You don’t want to go away too, do you?”

Jesus replied to them, “Didn’t I choose you, the Twelve? Yet one of you is the Devil!”

He was referring to Judas, Simon Iscariot’s son, one of the Twelve, because he was going to betray Him.

But one of the Twelve, Thomas (called “Twin”), was not with them when Jesus came.